Of all the responsibilities of a president, none is greater than his role as commander in chief of the armed forces. Whether the setting is Vietnam, the Persian Gulf, or Bosnia, the president must make agonizing decisions about whether and when to put Americans in harm's way. Some presidents have risen to greatness as commanders in chief. Others have gone down in history as failures because of their military defeats. What makes a successful commander in chief? Drawing on original research in presidential archives, James Arnold offers four provocative case studies of American presidents tested in the crucible of war. Since the days of the Revolution, Americans have been ambivalent about the power of the military, presenting a perennial challenge to presidents. George Washington had to face critics and doubters in the Continental Congress as well as the mighty British Army. As president, he saw his forces suffer embarrassing defeats in conflicts with frontier Indians before a final and decisive victory. James Polk, a president with no military experience, oversaw a stunning triumph in the Mexican War, helped by his ruthless manipulation of public opinion. But Lyndon Johnson, for all his political skills, saw his presidency broken by the war in Vietnam and his inability to marshal support at home. Most fascinating, perhaps, is the case of Jefferson Davis, president of the Confederate States of America. Unlike his opponent Abraham Lincoln, Davis had been a war hero and a renowned Secretary of War. Yet Davis failed as commander in chief and doomed the Confederacy to defeat. Focusing on key battles from Trenton to Ia Drang, Arnold combines political analysis with gripping narratives ofcombat. The result is a compelling history of how presidents weigh political pressures against military realities - and how their decisions play out for the men and women in the line of fire.